sarkas.potentials.egs.egs_force#

sarkas.potentials.egs.egs_force(r_in, pot_matrix)[source]#

Numba’d function to calculate the potential and force between particles using the EGS Potential.

Parameters

  • r_in (float) – Particles’ distance.

  • pot_matrix (numpy.ndarray) – EGS potential parameters. Shape = 6.

Returns

  • u_r (float) – Potential.

  • f_r (float) – Force.

Examples

>>> from numpy import array, pi
>>> from scipy.constants import epsilon_0
>>> r = 2.0
>>> alpha = 1.3616
>>> lambda_p = 1.778757e-09
>>> lambda_m = 4.546000e-09
>>> charge = 1.440961e-09
>>> c_const = charge**2/( 4.0 * pi * epsilon_0)
>>> pot_mat = array([c_const * 0.5, 1.0 + alpha, 1.0 - alpha, 1.0/lambda_m, 1.0 / lambda_p, 1.0e-14])
>>> egs_force(r, pot_mat)
(-0.9067719924627385, 270184640.33105946)